Bryn Oh's prim reduction trick

[Dot Macchi]

A post on Nalates' blog alerted me to this prim reduction trick described by Bryn Oh. Here's the link to the original post:

Bryn Oh: Prim reduction trick

The trick is to switch the physics of a regular-prim-based build from "Prim" to "Convex hull".

One of the commenters notes that this won't work with sculpties -- instead it will increase the prim count.

[Danko Whitfield]

I'm not sure how long the convex hull trick has been around but I've been using it for several months in Second Life.

I believe you can only use it with "plain" prims. You are right, it cannot be used with sculpties. If I recall correctly, it doesn't work on a prim with a script in it. Nor on certain other types of prims though I'm not sure which. I think when you are working with certain types of window textures there is a problem, for example.

But it is a handy trick in SL for sure. Of less value in Kitely because we have more prims to work with in most cases. Though, I guess if you have a 4x4 region, convex hull would be handy there.

(Edited)

[Ozwell Wayfarer]

I also have been using this trick in SL for a while and became quite well versed. Basically, you can apply the trick to standard prims, but avoid cylinders and torvus as they naturally have a higher render cost. Also try to avoid prims which contain scripts. Monitor your LE carefully, as it can work the other way too, bumping the prim count UP significantly. Link the prims then change the physics and watch it drop in half! I often build now in 2 linksets. one convex, one standard.


on average you should notice a reduction of around 35% on a build which uses "standard" prims. super useful in SL; and still a nice trick here too if you want to pack a region to the gills *ponders a 4000m tall sim-wide skyscraper.*

[Phaedra Electra]

I use this in SL all the time, you can do it with cylinders if there not hollowed, cut in half should be ok too, torus, and tubes can some times be included in a link set with other prims set to convex, and not have the count go up if their set to type none. I went to test it in Kitely after seeing this post and I can't even get 2 boxes to change their count when set to convex. I all so noticed that my viewer(firestorm) is not showing the LI ether, I have to go to more info to see the LI, then can't see the weights of selected. It's my first day in Kitely so just trying to see whats different. Not sure if what I'm seeing is just how things work here or may be need a different viewer?